"Time Travel" [Archive] - Flash Flash Revolution

[TeRa]

11-30-2008, 10:17 AM

Nima was a being from the future, many many years into the future, his stepmania skills were alright for his time, he would be considered a low-middle class player. Nima, getting sick of people ignoring his scores like 14 perfects on 0x1311, saved up his lunch money for several years until he could afford to build a rocket shuttle that moved so fast he could travel faster than light and eventually see back to our current time. Nima did just this, and using his state of the art wireless internet connection that could pick up a connection from anywhere in the universe, he played stepmania in the year 2003. Playing to only get bad scores to look new to the game, Nima wasted a little under 3 years gaining respect in the past stepmania community he had time traveled to. He eventually became the worlds best stepmania player, and could finally show his skills from the future from which he came. Nima made many videos to prove himself legit beforehand, he posted some scores, each better than the last, eventually, his bad 14 perfect score from the future he posted. People had already started to become suspicious by this point, and even more people had been convinced by this score. Nima, not knowing what to do because his camera had broken and he was stuck in space, he couldn't make a new video to prove his legitimacy. Instead of saying that because people would believe he was lying, Nima claimed his past videos are all the proof anyone needed, he had made no mistakes showing judge/.ini in those videos on good scores he claimed. Tsutter, unconvinced by Nima's excuse, continued to call bs upon Nima, as well as many, many more players. At this point, Nima had started to realize some of the differences of the future because of what he had done to the past. Nima knew what he had to do, lie to everyone, but give them what they wanted, and say that he wasn't legit. Nima did this, and saved the future from himself.
Nobody knows for sure what has become of Nima since these events, many believe he still floats around in his space shuttle, commenting on random youtube videos every now and then, other believe he returned back to his own time, and continued to play stepmania.

Heartseeker7

11-30-2008, 10:18 AM

The school's old Earth Systems teacher explained this in class once.
It has always fasinated me.
I would like to see the Big Bang more then anything.

dandandamdandan1111

11-30-2008, 10:19 AM

i can see where you are coming from on this. of course its impossible, butthe theory is sorta probable. if only there could be such a high powered telescope to actually see so far. you would most likely be able to see into the past because the light that the earth gave away 10,000 years ago would be shown if you are 10,000 light years away.

gausmaster

11-30-2008, 10:26 AM

devonin

11-30-2008, 10:43 AM

I'm not sure what you're building a window out of that holds up in vacuum at a velocity faster than the speed of lgith, but there would be plenty of light on all sides of you, just not the same light that you'd see if you were stationary.

You won't be able to tell what you're looking at in the same way that just driving very fast at normal Earth speeds starts to create tunnel vision and blur what you can see around you.

Also...the important thing you seem to be missing in the OP is that light is not the same thing as images. Moving away from the Earth extremely fast until you've "passed" the light that is a million years old is something you can do in theory, except what you're really doing is moving away from the -sun- extremely fast until you've passed the light that is a million years old, and so you'd be able to see, um...some light that is technically old.

If you focused your super powerful, incredibly accurate telescope back at Earth and looked at it, you'd get -A clear image of Earth right now exactly as you left it- (Or potentially a few seconds after you left it depending I suppose on how long it took you to travel that far away.

What you're suggesting is somewhat analogous to saying "If I follow a river really far down from the lake, and then look at the water, can I see the lake"

Yes, it took the light emitted from say, some star far away, so long to get here that it may have already gone nova and we don't know because the light from the explosion hasn't reached us, but if you were to travel there at many times the speed of light, it would have still already gone nova, just as you approached it, you'd see the star's development accellerating because you were catching up to the light it was emitting right now.

Going really fast doesn't actually turn time backwards for everyone but you, as much as some bad sci-fi would have you believe. The best you can do in terms of going faster than light is to use it to functionally time travel into the future.

Heartseeker7

11-30-2008, 10:47 AM

Another discussion totally obliterated by Devonin's great mind.

kmay

11-30-2008, 11:09 AM

Another discussion totally obliterated by Devonin's great mind.

yea, but the theroy he is saying still makes sense. No one knows whether this is true or not because we havent done it, but i do agree the light from the earth would be so spread out, looking trough a telescope, that everything would be blurry and the only thing you would see is light. Like when you look at the planets in the sky its just light even though they aren't stars.

devonin

11-30-2008, 03:51 PM

No one knows whether this is true or not because we havent done it

Nobody knows whether this is true or not because our understanding of physics says it is completely impossible to go faster than the speed of light.

tsugomaru

11-30-2008, 06:05 PM

That's because we can only perceive information traveling slower than the speed of light.

~Tsugomaru

tha Guardians

11-30-2008, 06:32 PM

Nobody knows whether this is true or not because our understanding of physics says it is completely impossible to go faster than the speed of light.

Well we still have no evidence that are only 3 spacial dimensions. As long as we're not wiped out before we get the chance, I'm sure we'll get to a point where the speed of light is laughable.

kmay

11-30-2008, 06:39 PM

if we are speaking physics then the g force our bodies would exprience would crush are bodies, so yes we could not travel any where near the speed of light...

gausmaster

11-30-2008, 08:30 PM

if we are speaking physics then the g force our bodies would exprience would crush are bodies, so yes we could not travel any where near the speed of light...

I do not agree with this. The acceleration wouldn't have to be any more intence than a normal rocket, just (hypotheticly speaking) the acceleration would probably take longer.

I am a big fan of really really old movies. The some of them about space travel (before we actualy did it) talk of how the forces over 5 G's would kill a man in seconds.
We know that man can survive (with injury sometimes) ejecting out of a jet aircraft. If I remember right I think that is a short burst of 200+ G's.

If you can base your statement on fact I really would like to look at your sources.

You can't make a rocket shuttle go 1000000000000000000000 per second.... Yeah, that's 10 with 21 zeros behind it, AKA the speed of light.

to this I answer...

I know there are a couple impossibilities in this idea but please dont get hung up on them.

who_cares973

11-30-2008, 08:36 PM

we are always looking into the past no matter what

virus003

11-30-2008, 08:44 PM

You can't make a rocket shuttle go 10000000000000000000000 per second.... Yeah, that's 10 with 21 zeros behind it, AKA the speed of light.

tsugomaru

11-30-2008, 09:25 PM

You forgot the units. You can make any number seem big if they are measured in units as small or smaller than picometers.

You wouldn't die from the "g-force" unless you went from 0 to light speed within a matter of seconds. The g-force deals with acceleration and one g is 9.8 m/s^2. If you can steadily accelerate to the speed of light, then it shouldn't be a problem. Although you can't feel it, we're traveling through space at well over a hundred kilometers per second, but we don't experience any g's because we're not accelerating much.

~Tsugomaru

Reach

11-30-2008, 09:38 PM

This is somthing I have been pondering for quite some time and I would like imput from a few high-level thinkers.
I know there are a couple impossibilities in this idea but please dont get hung up on them.
When you see a star at night, the light you are seeing is not what is happening right now but what was happening (perhaps) millions of years ago based on the speed of light and the extreme distance betwine the Earth and most stars.
So here is my theory.
Assume (by some freak act of phisics) that we found a way to rocket a shuttle many times faster then the speed of light. If we shot this shuttle very far away from earth and passed light for a long period of time would we be able to eventualy stop and (with a very powerful telescope) look back at the earth as it was thousands or perhaps millions of years ago? Just like we on Earth can see the birth of a star that has most likely already died out in real time, could we look back on Earth and see such things as living dinosaurs, or the Battle of Thermopylae? Or possably see yourself playing outside as a child? I'd like to hear your ideas.

Leaping over all of your impossibilities, yes, you could do this.

However, it would never happen, given they are impossibilities. We don't need to get hung up on breaking the speed of light - that's not the real problem (Sure, you can't break the speed of light across the shortest possible distance between two points in flat three-dimensional space, ever, but that doesn't mean it's impossible to find a faster path between those two points and beat light there). The real impossibility is this telescope that will intercept the incredibly old light. There are just too many problems with this, such as the myriad of obstructions in space that would prevent that light from ever getting to your telescope. You'd never be able to get a clear image of the surface of the Earth regardless of the telescope strength.

Crashfan3

11-30-2008, 10:14 PM

The focus of this confuses me, as I don't have the physics knowledge to give myself a clear explanation.

If we can see bodies of space that existed millions of years before mankind, then given the amazing technology, we should be able to see images of the earth in previous states, but I have no knowledge to back that up. HOWEVER, when the OP spoke of going faster then the speed of light and then stopping to look at the earth. Wouldn't light catch up with you in less than a second once stopped? If so, wouldn't that result in seeing absolutely nothing from the telescope, or images of the earth changing so fast that the human mind couldn't comprehend it happening?

tsugomaru

12-1-2008, 02:44 AM

The reason why we are able to see light from millions of years ago is because that's how long it took to travel from its source to the Earth.

~Tsugomaru

Patashu

12-1-2008, 03:53 AM

This is somthing I have been pondering for quite some time and I would like imput from a few high-level thinkers.
I know there are a couple impossibilities in this idea but please dont get hung up on them.
When you see a star at night, the light you are seeing is not what is happening right now but what was happening (perhaps) millions of years ago based on the speed of light and the extreme distance betwine the Earth and most stars.
So here is my theory.
Assume (by some freak act of phisics) that we found a way to rocket a shuttle many times faster then the speed of light. If we shot this shuttle very far away from earth and passed light for a long period of time would we be able to eventualy stop and (with a very powerful telescope) look back at the earth as it was thousands or perhaps millions of years ago? Just like we on Earth can see the birth of a star that has most likely already died out in real time, could we look back on Earth and see such things as living dinosaurs, or the Battle of Thermopylae? Or possably see yourself playing outside as a child? I'd like to hear your ideas.

yes that's right, and in fact if you can send signals at superluminal speeds back to earth just like you brought your rocket to such a speed you would be able to interact with earth's past - time travel
assuming special relativity holds FTL leads to time travel but it also means you've lost causality, as effect can now precede cause. that's generally not a good thing

ryanisadouche

12-3-2008, 05:21 AM

Also ponder this. If you were going faster than the speed of light and you looked out a rear window toward the earth that you are speeding away from would you be able to see anything at all while you were moving? Would it be complete darkness because no light is hitting you?

If you looked out the back of your rocket, since you're moving faster then light, the current light wouldn't have reached you yet and you would see what was there in the past. In other words, you'd see your own rocket travelling.

I could be horribly wrong but i think it makes sense given your original theory.

If you focused your super powerful, incredibly accurate telescope back at Earth and looked at it, you'd get -A clear image of Earth right now exactly as you left it- (Or potentially a few seconds after you left it depending I suppose on how long it took you to travel that far away.

I think he meant using the same technology we use today. I wont pretend to know anything about astronomy, but logically it should be common sense. If we look at Star X from Earth, we'll see it as it was in the past n years ago, so if we could hypothetically relocate instantly to Star X, we would see Earth as it was n years ago too.

A telescope could never be made to see Earth as you left it, because in our hypothetic situation we have travelled faster then the light that is present time . A powerful telescope cannot make light speed up and reach its lenses faster, it can only magnify the light that is there at the moment. You would be seeing "old light", as you put it, which could potentially be magnified to see a clear image (given a path of space debris was somehow cleared). It wouldn't be time travel, but just viewing the past.

Patashu

12-3-2008, 05:30 AM

It wouldn't be time travel, but just viewing the past; you could never interact with anything you saw, since in present time nothing you see exists.

assuming special relativity holds true, if you can travel at superluminal speeds and send a superluminal signal or object you could interact with Earth's past

you need to understand the lorentz transformation for it and why it's a consequence of special relativity but: http://www.theculture.org/rich/sharpblue/archives/000089.html

gausmaster

12-3-2008, 06:31 AM

assuming special relativity holds true, if you can travel at superluminal speeds and send a superluminal signal or object you could interact with Earth's past

I am by no means an expert at any form of phisics or relativity, but I have a very serious problem with this theory.
I do not belive that any interaction with the past is possible, because I belive that time is stable and consistant. If you were to fire an object at earth at 40X the speed we were traveling it would hit the earth in "real time". If we could comunicate instantaniously with earth then that signal would be going infinity miles an hour, but still you would only be speaking with people on earth in "real time".

MrRubix

12-3-2008, 06:37 AM

Assuming we could "get ahead of light" and somehow wind up on the other side of old light from years past, I don't think we'd be able to see anything meaningful. I think such light would have been dispersed and manipulated to the point where, even with a powerful telescope, we'd be unable to make out anything at the level of detail required.

We can see the light from things occurring years and years ago -- including things that could have already gone nova by now, but I can't think of an example where we have seen light from the past from an object comparable in size to the earth with the same level of detail. Normally when we look at "old light," they're for large-scale things where any small-scale high-level detail loss via light dispersion is made up for by the sheer AMOUNT of light coming in that makes up the larger image which, from our planet, makes up for a detailed picture. I would assume that for high-level detail, the light from something as tiny as our earth would simply become too dispersed/mangled to see. I'd think of it as trying to view crappy pixel art at high resolution. It's still going to be crappy pixel art.

Patashu

12-3-2008, 07:07 AM

I am by no means an expert at any form of phisics or relativity, but I have a very serious problem with this theory.
the fact is that if
-special relativity holds true
and
-we can travel at superluminal speeds
then
-we can send signals back in time (time travel)

it is a consequence of the theory deal w/ it

note that we don't have any physically plausible methods of achieving superluminal speed

Cavernio

12-5-2008, 07:41 AM

About what you would see if you were moving faster than light, I agree with gausmaster in that you would simply not see the light you're moving away from. Even a beam of light that is 0.0000001mm away from your eye will never be able to reach your eye.
You wouldn't totally see nothing though, because what our eyes pick up is more than the 180 degrees in front of us. We actually see about 10 degrees behind us on either side, http://en.wikipedia.org/wiki/Visual_field , so in those 10 degrees, we'd see light. As a side note, the light we would see if we looked forward would be at least twice as 'bright' because we'd be seeing at least twice as much of it in the same amount of time.

I got into a discussion about this last night, and the other person said that we would be seeing light all distorted, and they gave an example which this morning I realized was incorrect. See, I've been thinking about this problem like light has individual particles. He was thinking about the light simply surrounding us, like, say, water in a stream. If we sit in a stream, we're surrounded by the water, just like if we sit in light, we're surrounded by light. Then he said, pretend we're moving in the stream, swimming downstream with it. At this point, if we're actively swimming in it, we're moving faster than the water is. Yet we're still surrounded by water, there's water touching us behind us. This stumped me for awhile, but there's one serious problem with this: the water changes speeds depending on where it can go. The moment we'd move in the water, the water comes flowing in behind us at a much much faster speed than it flows downstream. Light, however, doesn't do that, because we're saying we'd be travelling faster than its maximum speed.

John McPain

12-5-2008, 08:05 AM

This is Gausmaster's new account.

Even a beam of light that is 0.0000001mm away from your eye will never be able to reach your eye.
You wouldn't totally see nothing though, because what our eyes pick up is more than the 180 degrees in front of us. We actually see about 10 degrees behind us on either side, http://en.wikipedia.org/wiki/Visual_field , so in those 10 degrees, we'd see light. As a side note, the light we would see if we looked forward would be at least twice as 'bright' because we'd be seeing at least twice as much of it in the same amount of time.

I agree 100%, but what (in your opinion) happens to the light inside of the shuttle?

Cavernio

12-5-2008, 08:42 AM

The light sources inside the shuttle would still be emitting light that would bounce of the walls and other objects inside it, so there'd still be light 'trapped' inside and moving with you. My very first thought on this is that it would look the same as if we weren't moving, at least once we reached our travelling speed. I don't think we'd get any doppler effect or anything, because relative to the light, our movement hasn't changed at all.
As for light that enters in the shuttle, and then would say, touch the wall...uhhh...I dunno! I don't know enough about the properties of light to answer that really. It light were matter, then it'd get 'stuck' to the wall. But light's not matter, so I dunno. I suppose if it were still to get 'stuck' to the wall, then there'd be a serious problem, wouldn't there be? The shuttle would melt from the heat from all the trapped energy or something.

This seems similar to another problem I was given in my grade 7 science class actually, one which I still don't think was answered properly at the time. (I'm not sure how it's similar, but it made me think of it.)
You have an airtight jar on a scale with a fly sitting on the bottom. Does the scale pick up the weight difference if the fly takes up and is now hovering in the air? Now, I *think* I was told at the time that yes, it did pick up the weight difference, but I have no idea who actually tested this or not. If the jar isn't airtight, than I think it would notice the difference for sure. Also, there's the extra pressure of the air being beat down by the fly onto the scale which you'd have to take into account, right?

John McPain

12-5-2008, 09:08 AM

Mythbusters did this. They concluded that there is an aberation picked up by the scale but that was caused by momentum differences.
source = http://kwc.org/mythbusters/2007/04/episode_77_birds_in_a_truck_bi.html

Cavernio

12-5-2008, 09:16 AM

Bah, you posted too fast! I can't edit my other post anymore now. Not all matter would stick to the wall, if it were elastic matter, it might not. If we could call light matter at all, would it not be like 100% elastic matter and also bounce back at light speed + shuttle speed? If this is the case, then again, because we're also moving, to us, the light would just be moving at light speed.

Shaydow

12-5-2008, 04:32 PM

http://www.youtube.com/view_play_list?p=E8EFE6A7EA479666

I love this show, its one of the few things I personally set our dvr here at home to record ( that and House :P ).

A great walkthrough on Light and its speed, how the Universe can bend to accomedate the speed of light, how the Universe itself actually is expanding FASTER then the speed of light, and other neat stuff.

Enjoy.

QED Stepfiles

12-5-2008, 06:26 PM

This is somthing I have been pondering for quite some time and I would like imput from a few high-level thinkers.
I know there are a couple impossibilities in this idea but please dont get hung up on them.
When you see a star at night, the light you are seeing is not what is happening right now but what was happening (perhaps) millions of years ago based on the speed of light and the extreme distance betwine the Earth and most stars.
So here is my theory.
Assume (by some freak act of phisics) that we found a way to rocket a shuttle many times faster then the speed of light. If we shot this shuttle very far away from earth and passed light for a long period of time would we be able to eventualy stop and (with a very powerful telescope) look back at the earth as it was thousands or perhaps millions of years ago? Just like we on Earth can see the birth of a star that has most likely already died out in real time, could we look back on Earth and see such things as living dinosaurs, or the Battle of Thermopylae? Or possably see yourself playing outside as a child? I'd like to hear your ideas.

So, on the one hand, as you've put it, then yes, it's perfectly possible. Information cannot travel at past the speed of light, and so if we were somehow able to overtake the "information" of times past, then theoretically it would be possible to see the past. Of course, this is a bit of faulty reasoning, since if we were to go past the speed of light, then we in effect (as information) would be violating this rule...

In other words, it's not really meaningful to say "would this happen if we could travel past the speed of light," because if we could travel past the speed of light, then information can too, and really the entire discussion becomes a bit pointless.

EDIT: Whoops, for some reason I thought that I was responding to the most recent post in this thread, rather than the first post... sorry if I broke the flow...

Cavernio

12-6-2008, 04:29 AM

Afrobean

12-6-2008, 05:49 AM

note that we don't have any physically plausible methods of achieving superluminal speed
Sure we do. We just don't have any practical applications of these physically plausible methods.

:)

Incidentally, wormhole travel: does this fall under the category of superluminal? Your own speed would not be greater than the speed of light, but you'd still be able to arrive at a destination before light.

Patashu

12-6-2008, 06:21 AM

Sure we do. We just don't have any practical applications of these physically plausible methods.

:)

Incidentally, wormhole travel: does this fall under the category of superluminal? Your own speed would not be greater than the speed of light, but you'd still be able to arrive at a destination before light.

I think I mentioned that one yeah

it's superluminal with respect to an outside observer but not for the wormhole traveller itself

legato210

12-7-2008, 12:55 AM

well since this is all speculation, I found a video you might be interested in watching.

this man is a genius.

http://www.youtube.com/watch?v=w-prt5d6m6s

devonin

12-7-2008, 01:44 AM

Whether you think he's a genius or not, a clip about futurists has nothing really to do with what we're discussing here.

slipstrike0159

12-7-2008, 02:56 AM

Nobody knows whether this is true or not because our understanding of physics says it is completely impossible to go faster than the speed of light.

I was going to post the video i saw on the discovery channel a while back called the universe, but i was beaten to the punch. This may now be approaching the realm of not true because according to the video, some scientists now believe that in the big bang theory (for matter of reference) the explosion threw particles out at speeds faster than the speed of light.

One thing i think is important to keep in mind with this whole theory (obvious impossibilities aside) is that you all refer to the analogy of seeing a star that may have already went through a super nova and its 'old light'. When you try to apply this logic towards trying to see 'old light' i think that its important to realize that, unlike a star, the earth does not give off light going at light speed. It is reflected light from our sun. As small of a difference as this may be, you would have to consider the fact that if you try to look at light coming off from the earth it might go less than the speed of light.
As a point of clarification, we can actually slow light through different mediums. So then would it not be possible that the light coming off of the earth would be going at speeds that are less than the speed of light in a vacuum? Of course thinking in terms of it as either going through the atmosphere or at least touching it enough to use the particles it hits letting it slow down.

Also, im a little shaky on the whole subject of 'looking back at the earth' after speeding away from it at faster than the speed of light. To be able to see that specific planet wouldnt you have to have a direct connection of light to it so you can actually 'see' it? To explain, of course you would have light still hitting you from different directions, but i was always under the impression that to see something through a telescope you have to have its specific light hitting you already. If you have breached the light that is reflected off of the earth (of course only considering you got outside the original light reflected off of the earth at its creation) then you wouldnt be able to see the earth at all.

One last thing, simply enough, if you were moving at extremely fast speeds AWAY from the earth, why would it matter if that somehow allowed you to see it in its previous states? I mean, you wouldnt be able to communicate with it (for radio waves and the like travel MUCH slower), and you wouldnt be able to even get back to it without the light catching back up and it making no difference anyway.
To think of it realistically, look at the theory of relativity. Time moves relative to the observer right? So time would seem to move at different rates for someone on the earth as opposed to someone living on, lets just say, jupiter. Outsides the bonds of our earth we would be trying to time everything according to the system we use ON the surface of the earth which simply would not be the universal system of all the bodies in the universe. Our measuring system in accordance with the rest of the universe would feel rather useless for no matter how fast you are traveling through space, time will always feel different. Thus, time travel in essence would be a virtually useless argument outside the bonds of our own time system, or rather outsides the bonds of time relative to wherever you are.

Strider11o7

12-21-2008, 06:55 PM

Although I'm not saying that the OP's theory is possible, it would be much more efficient to just look at a clear, reflective surface from far away (like a man-made mirror and placed there or otherwise). It wouldn't require a rocket and you could look twice as far into the past, I think.

Hachi86

12-21-2008, 07:08 PM

i personally can't see any reason why OP's theory wouldn't work, with the proper assumptions. (FTL travel, indestrucible glass, etc).

He's just taking something we know for fact and applying it to something different. We are sure that we can see light from a million years ago, so why couldn't we go multiple times the speed of light and look back at light reflected from Earth from the sun? Same principle.

Again, with the proper assumptions.

devonin

12-21-2008, 08:10 PM

Why would seeing old light correspond to seeing an image of the Earth as it was when it was as old as the light is?

Afrobean

12-22-2008, 04:28 AM

He's just taking something we know for fact and applying it to something different. We are sure that we can see light from a million years ago, so why couldn't we go multiple times the speed of light and look back at light reflected from Earth from the sun? Same principle.
Because faster than light travel isn't possible in actual practice ("indestructible glass"... hah).

It also wouldn't be possible to see it with any sort of detail, so the whole point would be lost. You might be able to see THE EARTH as it was a very long time ago, but you wouldn't be able to see any sort of detail of things on the Earth.

In fact, I'd say the only worthwhile thing that could be done using this technique would be to get an image of Pangea as it actually was, but I would think that wouldn't even be possible since the distance required to "outrun" light that "old" would be too great.

Why would seeing old light correspond to seeing an image of the Earth as it was when it was as old as the light is?
Did you really ask that?

Because the light coming from the Earth that is that "old" would have reflected off of the Earth a very long time ago and thus, it stands to reason that if one saw or recorded that light, what you'd have is an image of the Earth as it was when the light reflected off of it. Assuming, of course, that nothing blocked the path of the light or diffused it or anything.

Speaking of which, how long of a distance would light have to travel before it would become useless for seeing this sort of thing? Obviously the great distances we're referring to would require a tool to see at all, but I mean... obviously if light travels in a straight line forever, it's not going to be "perfect" when it reaches the "end" of its eternal path, even if the light doesn't directly interact with anything. Y'know what I mean?

devonin

12-22-2008, 10:32 AM

Assuming, of course, that nothing blocked the path of the light or diffused it or anything. Why does it "stand to reason" that light which reflected off earth a long time ago captured and maintained an image of the earth at the time of reflection? I certainly don't have near enough an understanding of optics to say that with any kind of certainty. Do you?

QED Stepfiles

12-22-2008, 11:53 AM

Why does it "stand to reason" that light which reflected off earth a long time ago captured and maintained an image of the earth at the time of reflection? I certainly don't have near enough an understanding of optics to say that with any kind of certainty. Do you?

Yes, actually, it's true that unless we're assuming that light is traveling through a perfect vacuum, then there would be quite a considerable amount of scattering of that light as it goes through whatever it's going through. However, at the same time, I do not believe that such a concern is very relevant for the sake of this argument, since we are more or less trying to discuss this theoretically, and such discussion calls for ideal simplifications (such as assuming that the reflected light remains intact).

One thing i think is important to keep in mind with this whole theory (obvious impossibilities aside) is that you all refer to the analogy of seeing a star that may have already went through a super nova and its 'old light'. When you try to apply this logic towards trying to see 'old light' i think that its important to realize that, unlike a star, the earth does not give off light going at light speed. It is reflected light from our sun. As small of a difference as this may be, you would have to consider the fact that if you try to look at light coming off from the earth it might go less than the speed of light.
As a point of clarification, we can actually slow light through different mediums. So then would it not be possible that the light coming off of the earth would be going at speeds that are less than the speed of light in a vacuum? Of course thinking in terms of it as either going through the atmosphere or at least touching it enough to use the particles it hits letting it slow down.

No. You do realize that the index of refraction of air is around 1.0003. This means that light hardly slows down at all in the earth's atmosphere. And, once that light reflects out into space again, where we assume a vacuum exists, it would be going at its "normal" speed once again. Light's particle/wave duality prevents you from analyzing it in such terms as "Oh well it hits a lot of stuff so it must slow down." Once it escapes from a dense medium into a vacuum it will be going at "light speed" once again, regardless of how dense that medium was.

To think of it realistically, look at the theory of relativity. Time moves relative to the observer right? So time would seem to move at different rates for someone on the earth as opposed to someone living on, lets just say, jupiter. Outsides the bonds of our earth we would be trying to time everything according to the system we use ON the surface of the earth which simply would not be the universal system of all the bodies in the universe. Our measuring system in accordance with the rest of the universe would feel rather useless for no matter how fast you are traveling through space, time will always feel different. Thus, time travel in essence would be a virtually useless argument outside the bonds of our own time system, or rather outsides the bonds of time relative to wherever you are.

The earth travels at around 30km/s around the sun. Sure, this seems fast, but relativistically, this is really very, very slow. Time difference of just looking at some object in space is completely negligible, if we were to time such a phenomenon from earth and from jupiter. So yes, you are perhaps right that there is some discrepancy, but scientists don't really care too much about 0.000000000001 seconds. On such a macroscopic scale as watching a macroscopic event in space, such a small time does not matter (if we were talking about particle physics, however, this would be a different matter...).

Sorry I'm picking on you so much, slipstrike, but I'm a bit finicky about scientific detail, and you're way off the mark in presenting these scientific ideas.

Afrobean

12-22-2008, 12:58 PM

ShAiOnEi

12-22-2008, 01:18 PM

There is no way time travel could be executed unless you could find a way of manipulating space and time. As of seeing our selves in the past due to light travel speeds I find this a very hard task to do.

devonin

12-22-2008, 01:36 PM

Your contention is whether the light would be able to carry the image that far without dilution?My contention is whether the light "carries" the image at all in that kind of meaningful sense.

The impression I'm getting from the way this process is being described is like, "Light hits the planet, is reflected off, and goes out into the depths of space, and we're going to go supre fast past it, turn around and look at it!" I don't really see how that will let us see much of anything except "some light" even assuming we pretend that there's no diffusion at all.

I'm presumably just missing something integral in the process here. Do I assume instead that we're just going really far away and then looking at the actual physical location of the planet, and somehow will be seeing it earlier in its history because we went away faster than light? Even assuming we also corrected for the fact that Earth won't exactly be where we left it either.

Heartseeker7

12-22-2008, 02:28 PM

But if we could TRAVEL TO THE ENDS OF THE UNIVERSE faster than the speed of light, could we SEE THE BEGINNING OF TIMEEEEEEEEEEEEEEE?

This brings in a whole different topic of whether the universe goes on forever, or if it ends at a certain point. I personally would rather see whats on the other side of the "ends of the universe" then the beginning of time.

John McPain

12-23-2008, 10:37 AM

This brings in a whole different topic of whether the universe goes on forever, or if it ends at a certain point. I personally would rather see whats on the other side of the "ends of the universe" then the beginning of time.

I would rather keep the discussion on topic please?

obviously if light travels in a straight line forever

I know it doesen't help my case at all but light does not alwase travel in a straight line. Light can be bent from gravity and magnitism.
Source = http://van.physics.uiuc.edu/qa/listing.php?id=1170

devonin

12-23-2008, 10:42 AM

I suppose we also have toa ccount for the whole "Light can act as a particle and as a wave" thing. It seems like light as a wave would be the best source of the clear view you're supposing we might have, if simply because light as particles seems like it would be more susceptible to gravity and magnetism causing problems.

John McPain

12-24-2008, 08:20 AM

MDMAngel

12-24-2008, 09:01 AM

The reason why we are able to see light from millions of years ago is because that's how long it took to travel from its source to the Earth.

~Tsugomaru

Note: I didn't read every post, just up until this one.

I agree with that...

The only thing we are looking into the 'past' of is the present of what's up for the future, which makes it seem like the past... but time has not been distorted in any way.

Light doesn't travel through time, I believe. It's just a matter of the length of time it takes something to reach one place to another, in a revealing pattern.

Even if we could see into the past, there's no such thing as altering it...

If you could, altering the past, even just a TINY bit... it could cause devastating results worldwide... or could change for the better, but more likely would not. What is done is done.

8Shade8

01-13-2009, 02:33 AM

Here is a theory/question: Would you be able to see different parts of the past based on how you focused your telescope? The fourth dimension is too complex for us to contemplate and play with right now, but under the circumstances that we somehow had the technology to travel faster than the speed of light, and made it light years away from earth and then aimed a telescope at earth, or even our solar system, it would make sense that you could instantly watch hundreds of thousands of years go by, simply by adjusting the focus on your telescope. Zooming in would fast forward time and slowly zooming out would rewind time. Sounds fun right?

devonin

01-13-2009, 11:48 AM

From my understanding of time, objective time is objective time. Your subjective time runs at a different speed as your speed approaches and even though we think it can't be done, surpasses the speed of light.

What would have to happen, it seems to me, is that if you moved away from the earth at almost the speed of light, when you stopped, and "fell back into" objective time, it would be the case that X years had passed for you, and a number >X years would pass for everything else. That would technically be time travel into the future because you spent say 1 year in travel and the earth has gone and "aged" 50 years. If you were to look at the earth, you would see earth as it "is now" but because of the relativistic effects of near-lightspeed travel, you would see it seeming subjectively older.

It would follow, to me, that if faster than light travel -were- possible, that yes, you would technically be going "back" in time, but again, once you "fell into" normal objective timespace again, you'd still only see the earth as it "is now" but because of the relativistic effects of greater than lightspeed travel, you would see it seeming subjectively younger.

I still don't buy the idea that you could look physically at the light which has already reflected off the Earth and gone very far away just by catching up to it super fast, and still see anything at all except "some light, quite diffused, coming from thataway" The only way you could see Earth, it seems to me, would be to look at Earth, and you'd only see it as it was "at the time" you looked. No movie versions of Earth's development, you'd have to travel around more at either more than lightspeed to go backwards, or less than lightspeed to go forwards.

slipstrike0159

01-13-2009, 08:45 PM

All of this is, for the most part, just an idea because we wouldnt be able to test it out. However ill pose the question again, why does it matter what would happen? It would not be worth all of this effort to 'fly through space going super fast and look back' only to see earth at an earlier state (assuming it worked) unless you could watch life as it starts and develops. Even getting to this impossible point where we got past the old light to tack on the ability to have a telescope that could see microscopic cells and organisms grow would be too much. Even seeing pangea would give us what, very little information at most? The information that we would be able to learn would be not very usefull especially if you figure that once we get this technology we would have advanced to the point where we could figure it out without such a process anyway. Sorry if it seems like im ranting, but i just realized the pointlessness of it all.

Anyway, 'time travel' in the traditional media sense would suggest being able to do or see something in the past/future we didnt already know. This would then bring the point of if you did/saw something remarkable, would it alter anything or would everything stay the same because it was 'supposed' to happen. The biggest problem i have with time travel in the media sense is that if someone years in the future found out how to achieve something like this and the 'butterfly effect' came into to play then from the moment the technology was discovered until the end of time there would be infinite chances for something to go wrong. The worst of which being a catastrophy that ends the world for which all of us now would see as it unfolds thus making 'our' ability to get this technology unavailable or at the very least useless.

devonin

01-13-2009, 10:30 PM

Or we're just already living the reality that is the result of all current and future trips into our past.

Loverofstories

01-15-2009, 01:09 AM

Or we're just already living the reality that is the result of all current and future trips into our past.

"Reality is an illusion. Albeit a very persistent one."
-opinion from a scientist (albert einstein ;) ). Try non-sense. What currently see: stars AS they have shone millions of years ago (from another place made of many small images - if you have uber powerful telescopes you can see them as they are now).

Afrobean

01-15-2009, 01:58 AM

"Reality is an illusion. Albeit a very persistent one."
-opinion from a scientist (albert einstein ;) ). Try non-sense. What currently see: stars AS they have shone millions of years ago (from another place made of many small images - if you have uber powerful telescopes you can see them as they are now).
You have a telescope that can increase the speed of light to be superluminal speeds? How does that work? Also, how does it speed up the light that is still many light years away? I might be able to believe in a telescope which can increase the speed of the light within it, but how can a telescope speed up light which is far away from it?

Sol_Solis

01-15-2009, 02:08 AM

You have a telescope that can increase the speed of light to be superluminal speeds? How does that work? Also, how does it speed up the light that is still many light years away? I might be able to believe in a telescope which can increase the speed of the light within it, but how can a telescope speed up light which is far away from it?

Umm, as they appeared* - i think thats the correct tense.
Telescope uses curved mirrors! It does wonders, picture hubble as the most powerful with more mirrors and groovy technical things. If I could remember I could handle a more eloquent explanation, but basically you start with a curved mirror, light, and go from there (the light reaches the curved shape and the image becomes intensified and focuses it into a single one - how seemingly simple, we managed to get one IN OUTER SPACE!!!). It has more advanced operation features however, so now one can't say.
http://science.howstuffworks.com/telescope1.htm

~kitty~

01-15-2009, 12:40 PM

Or we're just already living the reality that is the result of all current and future trips into our past.

Then we find out about all future time travels to the past and detect that they'll arrive somewhere and we shoot them and kill them, then send a person into the future to shoot them again and what then?

We caused a paradox, so I doubt that's going to happen.

Plus the theory that no two entities can exist at the same time in the same place still stands, I believe.

devonin

01-15-2009, 04:06 PM

Then we find out about all future time travels to the past and detect that they'll arrive somewhere and we shoot them and kill them, then send a person into the future to shoot them again and what then?

We caused a paradox, so I doubt that's going to happen.

Plus the theory that no two entities can exist at the same time in the same place still stands, I believe.

Perhaps you misunderstand? The past that we experienced IS ALREADY THE ONE THAT HAS BEEN MODIFIED BY FUTURE TIME TRAVELLERS. That is, you cannot go back in time and change the timeline, because when you go back in time, what you did has already happened, since it is, after all, in the past. So any changes you were going to make ARE WHAT HAPPENED, and the resulting timeline which is our timeline is completely paradox free.

As for the theory, I think you mean that no -one- entity can exist in the same time and place as itself? Like, I can't go back in time to my own childhood and give myself some winning lottery numbers or something? Even if we grant that as correct, that still doesn't suggest any inability to time travel, so I'm not sure why you brought it up.

~kitty~

01-15-2009, 04:29 PM

slipstrike0159

01-16-2009, 04:08 PM

Perhaps you misunderstand? The past that we experienced IS ALREADY THE ONE THAT HAS BEEN MODIFIED BY FUTURE TIME TRAVELLERS. That is, you cannot go back in time and change the timeline, because when you go back in time, what you did has already happened, since it is, after all, in the past. So any changes you were going to make ARE WHAT HAPPENED, and the resulting timeline which is our timeline is completely paradox free.

As for the theory, I think you mean that no -one- entity can exist in the same time and place as itself? Like, I can't go back in time to my own childhood and give myself some winning lottery numbers or something? Even if we grant that as correct, that still doesn't suggest any inability to time travel, so I'm not sure why you brought it up.

Technically it all depends on what time the travelers from the -future- decided to go back to. They could have gone back to a period of time that is in the future for us but also that is in the past for them and we just havent realized it yet. Hence my theory of a doomsday event. I believe that with whatever amount of time that we have left in our (as in the earth's or humanity's) future, from the moment the said device is created to the point of its destruction there would be an infinite amount of time for something they do to go wrong. Even if you think of a good natured being going back to change something for the better, it could have many negative repercussions that werent considered. Not necessarily that it will lead to a cataclysmic event, but i believe the likelyhood if it would be very high.

Also, as far as the whole one entity existing in the same time thing, i think its important to realize that considering the matter involved it would just be like seeing a twin. Sure its the same person but the one from the future wouldnt have a huge "omg i looked into your/my eyes and now theres a paradox that ripped apart the space time continuum!" effect on interacting with his/her former self.

devonin

01-16-2009, 05:41 PM

It doesn't depend on the time travellers from the future going to a certain time or another. From the point of view of our fiction, it is meaningless to consider 'the repercussions' of time travellers travelling to a point which is still in our future, because our future is not a fixed series of events yet.

It is only when you are dealing with people who have travelled to -your- past, does one have to consider 'changing the timeline' in a way that potentially creates a paradox, and my assertion is simply that there can be no paradox because we are already living the results of any and all meddling that was done, or will have been done in our past at any given moment.

Put another way: Like the question of whether or not there is free will, or determinism (The answer to which is "Whether there is free will or not is irellevant because we have an incredibly persistant illusion of free will.") the question of whether or not time travellers to our past have changed the timeline is irellevant because we by necessity are the end product of those changes. If someone could go back and change our current fiction, the changes would cascade up in such a way that we WOULD NEVER POSSIBLY KNOW THERE HAD BEEN A CHANGE, so whether they CAN change things or not is irellevant unless you simply grant that any changes they make ARE what generated our fiction.

Oni-Paranoia

01-16-2009, 06:22 PM

If going back in time was even possible, someone from the future would be here. It seems as if before we'd ever learn how to do that, we hit extinction since we do not see anyone from the future here unless they have already changed the past before which brings us to today. So either they were before us or not at all because 1. its impossible or 2. humanity will seize to exist before its figured out

Time Travel in my opinion is impossible and ive been following along with this thread, mostly Devonin's post since they are logical to even my understanding. ++

devonin

01-16-2009, 10:41 PM

If going back in time was even possible, someone from the future would be here.How do you know they aren't?

Afrobean

01-17-2009, 12:44 AM

How do you know they aren't?
Probably because if you believe in a correcting time stream like that, a paradox would be unavoidable, and as Doc Brown put it, it would likely destroy the entire Universe.

If backward time travel is possible, it works on a branching system. If the time stream branches at points of backward time travel, it allows for instances of time dopplegangerisms without introducing the idea of a paradox. The future where the time traveler comes from need not exist in that iteration of time, because it DOES exist in another dimension where he came from.

DarknessXoXLight

01-17-2009, 01:32 AM

Wow dammit.
I was going to post my awesome explination but it looks like devonin has got it under control. xD

Izzy

01-17-2009, 11:15 AM

Time is just a concept. Not something you can go back in.

Oni-Paranoia

01-17-2009, 12:06 PM

Time is just a concept. Not something you can go back in.

Exactly, time is a mental aspect.

devonin

01-17-2009, 12:29 PM

Probably because if you believe in a correcting time stream like that, a paradox would be unavoidable, and as Doc Brown put it, it would likely destroy the entire Universe.

If backward time travel is possible, it works on a branching system. If the time stream branches at points of backward time travel, it allows for instances of time dopplegangerisms without introducing the idea of a paradox. The future where the time traveler comes from need not exist in that iteration of time, because it DOES exist in another dimension where he came from.

Or, as I said, this is already the reality that is a result of all time travel that went into our past. All the changes to the time stream happened, and this is the result. I don't get why that's such a strange line of reasoning to people. Any changes to the timeline of the -traveller- who came from the future are irellevant and not something we need to consider or account for, because the future is not fixed, only the past.

Time is just a concept. Not something you can go back in. We can already create a situation in which a person's subjective time differs from the subjective time of everyone else. The net effect has been a slight instance of time travelling to the future.

Afrobean

01-17-2009, 05:25 PM

Or, as I said, this is already the reality that is a result of all time travel that went into our past. All the changes to the time stream happened, and this is the result. I don't get why that's such a strange line of reasoning to people. Any changes to the timeline of the -traveller- who came from the future are irellevant and not something we need to consider or account for, because the future is not fixed, only the past.
Because if the time we have now is the result of the time line correcting itself on every backward time travel, THERE WOULD BE TIME PARADOXES. Did you see Back to the Future? That **** would never play out in reality. Marty would have gone back in time and the paradox would have become completely apparent the moment he saved his father from getting hit by the car. Time wouldn't wait and give Marty a chance to influence things. Furthermore, even if he had succeeded in putting his mother and father together, his interfering in the past would have caused a butterfly effect that would have, in all reality, change the genetic structures of himself and his siblings, to say nothing of the chance that he may have more or less siblings. His alterations to his parents' past could even have affected his younger self to such a degree that he might never have met Doc or might have decided not to go to Twin Pines Mall that fateful night, presenting an entirely different paradox possibility. The movie glosses over these facts because it would make for a very boring and stupid story.

The only chance of a correcting singular time line like you are describing would be for it to be paradox resistant. I think Futurama Bender's Big Score touched on something like this, but if I recall, the Universe just ended up ripping apart at the end anyway. Maybe a better example is the 2002 version of The Time Machine (honestly, it's the only adaptation I've seen). The guy builds a time machine to go back in time to save his fiancée. However, when he goes back in time and saves her, it turns bad anyway and she dies again in a different way, because if she never died in the past, he'd have never built the time machine. The Universe corrected the paradox by making it so that no matter how he influenced the past, she would die an accidental death to be the catalyst for him to build the time machine that would get him there.

Now, take a step back. How could the Universe "know" what to do? I'd have to say that this would only be possible with an all-knowing and all-powerful god who would watch over the time stream, one who can even override our apparent free will to ensure that paradoxes are explained out reasonably without logical contradictions.

We can already create a situation in which a person's subjective time differs from the subjective time of everyone else. The net effect has been a slight instance of time travelling to the future.
If you go at high velocities, time passes more slowly for you. Why then would you expect backward time travel to affect THE ENTIRE UNIVERSE? Isn't it much more likely that in traveling back in time, you'd branch off another path in the 4th dimension by way of the 5th, such that the only one affected by the alternate path through the 4th dimension was you? Again, subjective time dilation affects you rather than the Universe, so why would other variances in subjective time flow affect anything other than just you?

Or do you not buy into the concepts presented by multiple dimensions stacked upon each other? I think it's sort of silly to think that there could only be one instance of our reality that would need to be constantly written and overwritten as changes to history (or even future history) are made.

Oni-Paranoia

01-17-2009, 06:53 PM

If you go at high velocities, time passes more slowly for you. Why then would you expect backward time travel to affect THE ENTIRE UNIVERSE?

True.
Listen to a song (Monolith)
Listen to m1dy speedcore BS for the next 5 songs
Listen to monolith again

Concentration level effected?? Kinda like slowing down time in a way, but only for your instant, which means in anyone eles perspective your going rly fast. correct?

Afrobean

01-17-2009, 07:13 PM

True.
Listen to a song (Monolith)
Listen to m1dy speedcore BS for the next 5 songs
Listen to monolith again

Concentration level effected?? Kinda like slowing down time in a way, but only for your instant, which means in anyone eles perspective your going rly fast. correct?
No.

Time dilation is a scientifically measured phenomena. It can be measured by highly accurate clocks. Even without a person on board a high speed vehicle, time dilation could be measured by COMPLETELY OBJECTIVE equipment on board designed to measure time.

Actually... wow. Just thought of something. Time dilation on the Earth as a whole due to the planet's velocity moving through the galaxy. Is that possible or is the effect of it negligible?

Then again, everything is relative and there is no "standing" measurement for anything... even if time was dilated greatly, we'd have no measuring stick that isn't also bound by the same motion that the Earth is on track with through the galaxy.

devonin

01-17-2009, 09:44 PM

If you go at high velocities, time passes more slowly for you. Why then would you expect backward time travel to affect THE ENTIRE UNIVERSEIt was inherant in the nature of time travel as discussed in this thread, that you were being picked up and moved backwards in time from when you started, and deposited into the same world earlier in time. It still only effects you, not the entire universe, you singularly were moved to an earlier point along the spatial dimension that time is. The issue is then one of whether what you can do while there will have any effect on the rest of the timeline, and people propose all kinds of paradoxes involving killing your grandfather, or whatever to somehow suggest that time travel would either be impossible, or destroy the universe.

Because if the time we have now is the result of the time line correcting itself on every backward time travel, THERE WOULD BE TIME PARADOXES.

I don't think there would be. Remember, what we perceive as reality is, in my theory, already effected by any and all actions that took place "in the past" whether those actions were carried out by people native to that fiction, or people from the future of that fiction.

It isn't a matter of saying "What happens if in 100 years, someone developes time travel and tries to go back in time to prevent Hitler coming to power?" because the fact that Hitler -did- come to power already shows that nobody did such a thing.

Whether that's because time travel included some means of guarenteeing that time travellers couldn't interfere in any way, or whether there's a group from further uptime whose job is to fix things people screw up, or because someone in the future went back in time to stop Gordon Jones from coming to power, and as a result of that prevention, allowed Hitler to come to power instead is irellevant, because whichever of those things might have been true, the end result was OUR PAST AS WE RECORDED IT.

Were someone -ever- to go back in time to try and prevent Hitler coming to power, they clearly either changed their mind, were stopped, or failed in their attempt, because he did come to power.

There are no paradoxes, because the past is already fixed, it is static and objective AND INCLUDES ALL MESSING AROUND DONE BY TIME TRAVELLERS.

footbull3196

01-18-2009, 11:42 AM

Actually, time travel is possible.

BUT, it's so improbable that it will almost likely never happen.

Also, if you went back and, let's say, killed your grandfather, a new parallel timeline would be created where you are not born. I'm not exactly sure how that would end up, but it's still interesting.

devonin

01-18-2009, 03:06 PM

Actually, time travel is possible.

BUT, it's so improbable that it will almost likely never happen.Don't use absolute claims unless you can actually prove them. Please prove that your claim "Time Travel IS possible" is correct.

Also, if you went back and, let's say, killed your grandfather, a new parallel timeline would be created where you are not born. I'm not exactly sure how that would end up, but it's still interesting.I would instead suggest that the fact that you are alive clearly shows that either you never went back in time to try and kill your grandfather, or that you failed in your attempt to do so.

Which seems like the more likely explanation of your existance?

"I went back in time, and killed my grandfather, which to avoid a paradox, created AN ENTIRELY SEPARATE UNIVERSE in which I wasn't born, for the SOLE REASON of avoiding a potential paradox involving my not being alive in order to go back in time"

or

"Because I do exist, I either never attempted to kill my grandfather in the first place, or I tried and failed"

Afrobean

01-18-2009, 07:31 PM

Don't use absolute claims unless you can actually prove them. Please prove that your claim "Time Travel IS possible" is correct.
We're traveling through time right now naturally. We know that time dilation occurs at high velocities and that gives us a means to control time's flow to a degree.

The only thing we don't have an absolute theoretical mechanism for is backwards time travel.

I would instead suggest that the fact that you are alive clearly shows that either you never went back in time to try and kill your grandfather, or that you failed in your attempt to do so.
No... you're misunderstanding the concept of a branched time line. There would be two points in time and space, simultaneously existing at different places in the 5th dimension. One would be the time where your grandfather is alive and you are alive, and your future self makes a trip to the past. The other would be an iteration of reality where you seemed to have come out of nowhere, killed who would have been your grandfather, and the you that should have been born according to your native timeline would never have been created.

These potential time lines are all existing within the 5th dimension and it's just our path along the 5th dimension that defines what form our 4th dimension takes.

Which seems like the more likely explanation of your existance?

"I went back in time, and killed my grandfather, which to avoid a paradox, created AN ENTIRELY SEPARATE UNIVERSE in which I wasn't born, for the SOLE REASON of avoiding a potential paradox involving my not being alive in order to go back in time"

or

"Because I do exist, I either never attempted to kill my grandfather in the first place, or I tried and failed"
If you take backward time travel as a given, you cannot very well say "I either never attempted to kill my grandfather... or I tried and failed." There are very basic tests to try to create this sort of paradox which should be fail-proof. Again, I would say that the only way that the Universe would "know" how to prevent such a paradox would be if there was an all-powerful, all-knowing god of time.

And again, you are misunderstanding the concept of branched time lines. The time that you "created" actually already existed in one form in the 5th dimension and our actions through the 4th dimension just never caused it to come into being in our dimension. However, going back in time and causing a shift in the events of the past would cause the time line to shift in another direction. And even though the time line that we see as established time would have shifted to another place in the 5th dimension, our previous 4th dimensional reality would still exist at another point within the 5th. In truth, the only one who would be aware of the change would be the time traveller, who will be composed of matter from a different place in the 3rd, 4th, and 5th dimensions.

But really, the paradox is explained perfectly on a branched time line. You killed someone who was your grandfather, but in killing him, all you did was put that time line on alternate path in which you don't exist. The paradox is irrelevant here, because the you that killed your grandfather is known to have time traveled to that time from a time and place where that man would have been your grandfather. Think of it this way:

Your home is at a coordinate in reality which can be defined by a set of 5 dimensions, which for the sake of argument I'll call (0, 0, 0, 0, 0). Now, the point in reality where your grandfather was killed by a time traveler from what is for them an alternate future can be defined as, let's say (-1, -1, -1, -1, 1). All you're doing is moving from one point in reality to another point in reality. There is no wave of refreshing on the time line that makes the paradox destroy the Universe; this is not Back to the Future. And if there was a wave that refreshed the timeline, how long would that take? What would trigger it? Why do you believe the Universe KNOWINGLY avoiding a time paradox makes more sense than explaining that the person who killed the man who would have been a grandfather was a person from an alternate reality in the 5th dimension?

Have you seen Sliders? You know how they go to other worlds and things? I believe in most of the worlds they went to, that world's copies of them were ALSO traveling through worlds, but sometimes they weren't. What they were doing is foregoing time travel and just hopping into the same point in time and space at different points in the 5th dimension. Would you consider their existence and affecting those "alternate" time lines to be paradoxical?

devonin

01-18-2009, 08:49 PM

You could try not just reexplaining your point as though I fail to understand it, because I clearly do understand it. Instead, I was showing a way in which you can resolve the idea of a time paradox without having to presuppose the existance of multiple universes.

Nowhere in anything I said, did I even imply that the universe is in any way self-correcting, that the universe "knows" anything.

What I said was "The fact that you exist shows that you did not kill your grandfather"

There are very basic tests to try to create this sort of paradox which should be fail-proof.Such as? You're intending to just describe some set of circumstances where if you were hell-bent on creating a paradox you could simply arrange your attempt in such a way as to make it "impossible" to fail?

Afrobean

01-19-2009, 12:36 AM

Nowhere in anything I said, did I even imply that the universe is in any way self-correcting, that the universe "knows" anything.
If backwards time travel is possible (and traveling back in time can affect the "present" form of the person traveling through time, i.e., the time line refreshes itself when changed in the past) and it is still impossible to create a time paradox, that means that some sort of intelligence must be blocking it from happening before it can even occur. A time police system appears to be somewhat reasonable, but the refreshing nature and the paradox would still show through and by the time a time police force would be aware of an emerged time paradox, it would have already become apparent, turning causality on its head.

What I said was "The fact that you exist shows that you did not kill your grandfather"
And what I said was that your grandfather could simultaneously both live out his life or die in his youth by his potential grandson's hands. Schroedinger ****, I'll admit, but that is the view that I have on reality and the nature of higher dimensions. Do you not buy into the idea of multiple iterations of reality existing simultaneously in higher dimensions?

Such as? You're intending to just describe some set of circumstances where if you were hell-bent on creating a paradox you could simply arrange your attempt in such a way as to make it "impossible" to fail?
Uh, yeah. Like, go back in time one minute and shoot yourself in the head. The only way something simple as that could fail is:

#1: time travel skews into an alternate time line that exists simultaneously in another dimension
#2: backward time travel is not possible
#3: random chance
#4: some sort of intelligent and all-knowing/all-powerful being taking care to ensure that the attempt fails

The first example is what I think is right. The second is also a reasonable explanation. The third is essentially impossible, because even if the first attempt fails, given a potentially infinite number of attempts to create a paradox, there is no way, for example, that your gun would jam every time you try to kill your past self. The fourth jumps into the same area as intelligent design and there is no evidence to suggest that backward time travel has ever occurred in this iteration of reality, and if there were such evidence, an intelligent presence acting, even indirectly, would leave something to suggest that things we're playing out entirely on their own (for example, a person's gun jamming EVERY time they try to shoot their past self in the head would indicate something fishy).

devonin

01-19-2009, 01:24 AM

that means that some sort of intelligence must be blocking it from happening before it can even occur.Why? You're leaping to a "necessary" conclusion that I don't feel is necessary at all. I didn't say something -blocks- a paradox from happening, I said that the fact of the state of reality just happens to show that you didn't succeed.

Team A winning the championship shows that team B failed to win the championship without some outside force necessary having -stopped- Team B from winning. You can still observe the lack of championship trophy in the possession of Team B and conclude "They failed to win the championship"

you can even exhaust a huge number of individual reasons why in any given case of the above, team B failed to win. Maybe a player got injured, maybe the referee got bribed, maybe the team simply played poorly, and on and on and on. By the same token, you seem insistant that there has to be ONLY ONE reason why time paradoxes don't happen. You're simply going from "I could resolve to engage in some paradoxical act involving time travel" and then leaping directly to "It succeeded with no problems, what are the consequences" without considering the myriad reasons that could each individually be why each individual attempt has apparantly failed.

Uh, yeah. Like, go back in time one minute and shoot yourself in the head. The only way something simple as that could fail is:You're missing my point once again. I know what happened one minute ago, and it wasn't "A duplicate me appeared and shot me in the head" My point is thus: THE REASON WHY THAT IS THE CASE IS COMPLETELY AND UTTERLY IRELLEVANT TO ANYTHING.

The simple, observable fact of the matter is "One minute ago, I was not shot in the head" This is just the state of things. My chosen method to explain why "I did not shoot myself in the head one minute ago" is true is "Because I did not shoot myself in the head one minute ago."

You can try to call that tautological of you like, but it really isn't. As I mentioned before: For the same reason why the factual state of whether free will or determinism is true is irellevant (because we have either free will or a perfect illusion of free will) so too the case-by-case individual reason why time paradoxes haven't ever occured is irellevant.

It seems like you're assuming it goes "If someone were to go back from what is currently our future, to our objective past, and change something, effects would cascade forward, changing reality and potentially leading to paradox" And you choose to resolve those potential paradoxes by supposing that there must be alternate timelines causally seperated from this one which are the true destination for time travellers (Which to me, would make me say that they aren't actually time travellers)

Instead I'm saying "Any and all time travel that will ever occur in what is currently our future, to our objective past, has ALREADY HAPPENED AND LED TO OUR CURRENT REALITY"

Functionally, you left off #5: Reality as we percieve it is already the result of all time travel that will ever occur to a time before ours

Afrobean

01-19-2009, 03:52 AM

Why? You're leaping to a "necessary" conclusion that I don't feel is necessary at all. I didn't say something -blocks- a paradox from happening, I said that the fact of the state of reality just happens to show that you didn't succeed.
But in the case of history-altering paradoxes, it simply just "not happening" doesn't mean anything. Yes, I have never gone back in time and killed my past self (as per this iteration of reality anyway), but that does not mean that if I did attempt it, it would fail.

You're arguing that time paradoxes wouldn't be possible because history says that they haven't. However, this isn't a legitimate argument to make, because history also says that no one has ever traveled back in time, nor has anyone ever attempted to create a paradox.

In addition, I might add that ANY trip to the past where the intention is to change the past in ANY way would create a time paradox. In addition, the butterfly effect can cause unintended changes which could trigger time paradoxes by mere observation of the past.

Team A winning the championship shows that team B failed to win the championship without some outside force necessary having -stopped- Team B from winning. You can still observe the lack of championship trophy in the possession of Team B and conclude "They failed to win the championship"
This is time travel, buddy. Pure theory. You cannot draw parallels to established existence when we can't even say with certainty that backward time travel is even physically possible.

you can even exhaust a huge number of individual reasons why in any given case of the above, team B failed to win. Maybe a player got injured, maybe the referee got bribed, maybe the team simply played poorly, and on and on and on. By the same token, you seem insistant that there has to be ONLY ONE reason why time paradoxes don't happen. You're simply going from "I could resolve to engage in some paradoxical act involving time travel" and then leaping directly to "It succeeded with no problems, what are the consequences" without considering the myriad reasons that could each individually be why each individual attempt has apparantly failed.
Ok, given the situation that time travel is possible and I have a time machine, and Back to the Future rules of the flow of time apply:

I go back in time 1 minute to kill my past self. However, my future self's existence means that I must have failed in my past attempt to kill my past self, according to your "only one iteration of time that encompasses all future travels to the past". However, I wouldn't even have a memory of my future self having tried to kill me. And how would I fail? My gun would jam? My shot would miss? What happens when I try over and over? First attempt fails? Go back in time again and attempt a second try while my first try is busy failing. Second try fails? Go back in time again.

You're basically saying that I could try millions of times to kill myself in that instance, with millions of time doppelganger copies of myself attempt to kill the original. And all of the millions of the attempts would fail.

You're missing my point once again. I know what happened one minute ago, and it wasn't "A duplicate me appeared and shot me in the head" My point is thus: THE REASON WHY THAT IS THE CASE IS COMPLETELY AND UTTERLY IRELLEVANT TO ANYTHING.
What of a sniper shot? What about other ways in which one can affect time to cause a paradox without the past persons being aware of a future person's presence?

Anyway, you actually seem to be arguing that traveling back in time isn't even possible in your "yeah but then I would remember it" idea. History has no indication of a person traveling through time, so no, we don't remember it.

The simple, observable fact of the matter is "One minute ago, I was not shot in the head" This is just the state of things. My chosen method to explain why "I did not shoot myself in the head one minute ago" is true is "Because I did not shoot myself in the head one minute ago."
You cannot use the basic fundamentals of causality to explain a time paradox. Doing so in your manner indicates that backwards time travel is not even possible, and if you're going to take that stance, is discussion of the topic even worth putting forth?

The very reason that time paradoxes are worth thinking about and discussing is BECAUSE they throw causality into question.

It seems like you're assuming it goes "If someone were to go back from what is currently our future, to our objective past, and change something, effects would cascade forward, changing reality and potentially leading to paradox" And you choose to resolve those potential paradoxes by supposing that there must be alternate timelines causally seperated from this one which are the true destination for time travellers (Which to me, would make me say that they aren't actually time travellers)
Yeah, that's right.

Also notice that I never indicated that someone remaining in the same time and space, but moving across to an alternate time line (i.e. 5th dimension, ala Sliders), were time travelers.

And yes, if it is possible to travel back in time, and the future is not set in stone, and there is only one iteration of time that contains all time travels already, future trips to the past would have to cause a "cascading effect". This is how Back to the Future works, and this is why time paradoxes can cause a problem for this model of time travel.

Instead I'm saying "Any and all time travel that will ever occur in what is currently our future, to our objective past, has ALREADY HAPPENED AND LED TO OUR CURRENT REALITY"
Talking like that is the same as saying "traveling into the past that has already happened is not possible".

Functionally, you left off #5: Reality as we percieve it is already the result of all time travel that will ever occur to a time before ours
I left that out because it is related to the second conclusion: that time travel into the past is not possible. Yes, reality as we know it does contain all trips to the past thus far: ZERO.

devonin

01-19-2009, 04:42 PM

You're arguing that time paradoxes wouldn't be possible because history says that they haven't. However, this isn't a legitimate argument to make, because history also says that no one has ever traveled back in time, nor has anyone ever attempted to create a paradox.History doesn't say anybody has travelled back in time because we haven't invented time travel yet. History -has- recorded a number of people who claim to be from the future, but obviously, there is some difficulty in proving that. I think what you wanted to say was 'History shows no evidence of meddling by time travellers' to which I say "Of course not, because history is the result of that meddling."

but that does not mean that if I did attempt it, it would fail.I didn't say if you did attempt it, you would fail. I said that it didn't happen. I made no claims whatsoever as to the reasons why it didn't happen.

However, I wouldn't even have a memory of my future self having tried to kill me. And how would I fail? My gun would jam? My shot would miss? What happens when I try over and over? First attempt fails? Go back in time again and attempt a second try while my first try is busy failing. Second try fails? Go back in time again.

Think back one minute ago. Did a duplicate of you appear and try to kill you? No? Then you didn't go back in time from one minute from now and try to kill yourself. Whether you have a time machine, or Back to the Future rules apply, there is only one instance of each time-slice in the past, if it will have included time travellers in that time-slice, it already includes those time travellers.

No future you trying to kill you one minute ago? Then one minute-from-now-you doesn't make the attempt, or is stopped in the attempt in some fashion. Since I can't see into the future, I have no way to know which mechanism stopped you, but one hopes "Good sense and a desire to not create a paradox" featured highly in the reasoning.

History has no indication of a person traveling through time, so no, we don't remember it.History has no indication of what I ate for breakfast on September 2nd 1990, unless someone happens to remember for some reason (I dont' remember) that doesn't mean I didn't eat breakfast on September 2nd 1990. There are all kinds of historical accounts of things that -could- be interpreted as evidence of time travellers, but what are you looking for? Something in the writings of Aristotle about travellers from the future? A newspaper article "Men from the future captured in Nazi Germany!"

I said that our reality is already the result of any meddling that has or will have happened due to people travelling into the past. I don't see why there MUST be some sort of recorded evidence that these people were there, presumably if they went back in time they were clever enough to at least blend in.

And yes, if it is possible to travel back in time, and the future is not set in stone, and there is only one iteration of time that contains all time travels already, future trips to the past would have to cause a "cascading effect". This is how Back to the Future works, and this is why time paradoxes can cause a problem for this model of time travel.Let's try again: The cascade has already happened. We are already living the results of meddling with the past. There will be no sudden "new" cascade, because even if in 1,000,000 years, someone goes back to 1980 to screw with time, 1980 already happened, thus their visit already happened, thus any changes to the timeline already happened, leaving us with this one. Because that cascade happened, whatever the results of the cascade were, they did not include anything that would have led to the traveller not being alive to make the trip, because they did make the trip.

Talking like that is the same as saying "traveling into the past that has already happened is not possible".I disagree, considering my statement explicity assumes that time travel -is- possible.

Yes, reality as we know it does contain all trips to the past thus far: ZERO.And it contains all trips to the past that haven't happened yet: SOME NUMBER WE CANNOT RELIABLY ASSUME

Afrobean

01-19-2009, 07:01 PM

dev...

:|

All I'm hearing from you is "time travel into the past must not be possible."

So quick question. We take the assumption that backward time travel is possible, right? But the future is not set in stone? How is it then that the time travels from the future exist in the "stone" past if the future is not yet set?

Your whole argument is hinged on the fact that no one has actually traveled through time to the past and that no one has ever done so with a purpose that would cause a paradox. It doesn't even have to be something as absurd as killing your past self or killing your grandfather. Say you intended to go back in time to stop a terrible dictator from coming to power. The only way that such a trip could have NOT created a paradox is if the attempt to stop him failed. But then, if the people of the future are familiar with time travel and know the past is set in stone, couldn't the potential time traveler look at the past and notice that their attempt in the past didn't succeed and thus, never bother going back there in the first place, thus bringing about a completely different paradox?

Your model of time travel does not negate the possibility of paradoxes and it does not even come close to answering the questions presented by them. You're basically saying "no one's traveled through time, so no one created a paradox," then from there, you're taking the point that "no one has created a paradox" and saying that's because they haven't tried (or that they've all MIRACULOUSLY failed); you're making an assumption that is only possible as a good conclusion if you take the stance that time travel to the past is not possible.

And bro, let me tell you, if backwards time travel ever becomes possible, paradoxes are inevitable. The very nature of traveling back in time removes causality from the equation. Everything in the world follows the basic rules of cause and effect. But when someone appears from the future, there is an effect of additional matter and energy entering the 3rd dimension of the Universe without a cause-effect relationship in the 4th dimension.

Even if you go back in time only to observe and do not truly affect anything, butterfly effect can take hold and **** everything up just because of a few misplaced air molecules.

ps
And it contains all trips to the past that haven't happened yet: SOME NUMBER WE CANNOT RELIABLY ASSUME
Then why do you feel your conclusion is reliable to assume? You don't know how many trips might have happened in the future, why then do you feel it is reasonable to draw the conclusion that our past is riddled with the people of the future mucking about in it? There is no good evidence suggesting that someone from the future has ever mucked about in our past, so why would you come to that conclusion?

Really, man, you're making the assumption that people of the future would be noble and not **** with time, but do you really think that they would? Time travelers first steps would be to scientifically measure how they can affect the past, then, if it is safe, they'd go back and push humanity forward earlier on. They'd go back and erase the dark ages, push back the technological age a couple hundred or thousand years. They'd use their power to advance humanity in ways never before thought possible.

devonin

01-19-2009, 07:26 PM

I cannot conceive of a group of people "Noble enough to want to help humanity" via time travel who woudln't also be noble enough and intelligent enough to know that the potential risks are not worth it.

Again, since time travel does not currently exist, we really have no basis to assume that were it to be developed at some point in the future, that it would be in any way shape or form commonly accessible to whoever happens to want to use it.

I can't think of a thing which would be -more- prone to being regulated, controlled and monitored than the potentiality of backwards time travel. You're assuming just as many things about how time travel would work as you negatively accuse me of doing.

What's your basis for the assumption that time travel to the past needs to include the addition of matter and energy into the universe? Could time travel not potentially be developed in such a way as to render the traveller bound by "You can look but you cannot touch" not in the sense of "don't" but in the sense of "Is completely unable to"

If we're assuming that the universe has to follow its various laws that seem pretty much objectively true, why couldn't potential travellers be "out of phase" with reality as we understand it, able to move about and observe, but not actually able to effect anything by their presence? There's a potential version of time travel that is paradox free.

The main issue here is that you're saying "If we assume that someone travelling back in time must effect the timeline with consequences cascading" but even with my concept that time travel doesn't also include parallel universe travel, one of the potential explanations for the lack of paradoxes can easily be "Because travellers to the past can't actually interact with anything."

As I said more than once, the individual reasons why time travel in each instance of time travel hasn't led to a paradox don't especially matter, but I don't even mean they don't MATTER, so much as the fact that they are currently UNKNOWABLE so Agnostics ahoy, trying to imagine now whether it's time police, or failed attempts, or whatever doesn't actually DO anything. The lack of paradoxes shows that there is a lack of paradoxes.

Basically you're saying something like "You say that nobody has successfully carried out a paradoxical action while time travelling, but since -I- think that paradoxical actions are inevitable, the only way I can possibly accept your premise is if I assume that your conclusion is 'time travel is impossible'"

But since my conclusion is not "Time travel is impossible" but instead "Whether time travel is possible or not, nobody who has travelled to a time before right now has ever done anything paradoxical FOR WHATEVER REASON" So again, second thoughts, failed attempts, time police, time travel putting you out of phase, whatever the individual reasons happen to be, the evidence seems clear to me (Namely, that the universe hasn't exploded in a puff of logic) that whether you CAN create a paradox or not, no paradox has taken place before january 19th 2009 at whatever time you happen to see this.

footbull3196

01-19-2009, 07:41 PM

Don't use absolute claims unless you can actually prove them. Please prove that your claim "Time Travel IS possible" is correct.

Ok, well, I wasn't able to prove it yesterday since I somehow got banned, but anyways, there's this series called "Time" or whatever on the Science Channel with some Asian guy, and that's what they said on that show.

They also did some test with time. They took some thing that flashed numbers really quickly. Then they made a simulation to see if time slowed down during a near death experience. They took some guy up to the top of some tower and dropped him 100+ feet into a net. Not really a near-death experience, but he was stlil able to see the numbers.

Anyways, I thought that was cool, and on that show, they did say that time travel was possible, but just infinitely improbable. The odds of getting it right are like slim to none.

zhul4nder

01-19-2009, 08:01 PM

The term is sometimes used in popular media dealing with the idea of time travel, usually inaccurately. Most time travel depictions simply fail to address butterfly effects. According to the actual theory, if history could be "changed" at all (so that one is not invoking something like the Novikov self-consistency principle which would ensure a fixed self-consistent timeline), the mere presence of the time travelers in the past would be enough to change short-term events (such as the weather) and would also have an unpredictable impact on the distant future. Therefore, no one who travels into the past could ever return to the same version of reality he or she had come from and could have therefore not been able to travel back in time in the first place, which would create a phenomenon known as a time paradox.

-wiki owns you. Time travel is impossible because there would be no time to come back to.

devonin

01-19-2009, 08:25 PM

Footbull: "I saw it on TV one time" does not constitute proof, I'm pretty sure I've said as much to you once already. Also, none of your examples has the first thing to do with time travel. They have to do with testing the objective accuracy of subjective time dialation. Unfortunately for you, actual time dialation absolutely occurs and has been proven, involving very accurate clocks and very high speeds.

zhul4nder: They're just supposing that the mere presence of time travellers would change short term events, but even granting that, it in no way suggests that that butterfly effect would cause any kind of paradox, just that it would send a cascade of modified causes and effects moving forward. They could be very minor effects and still be effects. Also, just because the 'present' you returned to would not be the same as the one you left doesn't mean time travel is impossible, it just means time travel has consequences, which nobody here has been denying. Moreover, wiki owns nothing in this forum. Wiki's no more legitimate a source than anything else we're referencing or drawing from.

Afrobean

01-19-2009, 08:33 PM

I cannot conceive of a group of people "Noble enough to want to help humanity" via time travel who woudln't also be noble enough and intelligent enough to know that the potential risks are not worth it.
Like I said, ANY trip to the past could potentially cause a paradox, even if they do not intend to do anything.

And come on, you know scientists would be all over experiments involving time travel if they figured out how to do it.

Again, since time travel does not currently exist, we really have no basis to assume that were it to be developed at some point in the future, that it would be in any way shape or form commonly accessible to whoever happens to want to use it.
If ANYONE used it, it could cause a paradox.

And again, scientists would having nerdgasms all day long about experimenting with time travel.

I can't think of a thing which would be -more- prone to being regulated, controlled and monitored than the potentiality of backwards time travel. You're assuming just as many things about how time travel would work as you negatively accuse me of doing.
The only assumption I am making is that scientists would experiment with time travel if given the opportunity.

Do you disagree?

What's your basis for the assumption that time travel to the past needs to include the addition of matter and energy into the universe? Could time travel not potentially be developed in such a way as to render the traveller bound by "You can look but you cannot touch" not in the sense of "don't" but in the sense of "Is completely unable to"
I thought about this and I decided that such a development would probably need to be artificially crafted.

Anyway, if they're able to go back and observe things, how would it be possible for them to not affect ANYTHING? Are you suggesting that a function of the Universe would be to stop them from being able to act? What about basic ideas of physics? If a time traveler punches a caveman in the face, what happens to the energy that should be imparted to the past-dweller's face?

If we're assuming that the universe has to follow its various laws that seem pretty much objectively true, why couldn't potential travellers be "out of phase" with reality as we understand it, able to move about and observe, but not actually able to effect anything by their presence? There's a potential version of time travel that is paradox free.
You mean, like floating out in the fifth dimension, looking at cross-sections of the 4th?

That wouldn't be time TRAVEL though. That would be like looking at a photograph; just seeing the photograph isn't the same as BEING there.

The main issue here is that you're saying "If we assume that someone travelling back in time must effect the timeline with consequences cascading" but even with my concept that time travel doesn't also include parallel universe travel, one of the potential explanations for the lack of paradoxes can easily be "Because travellers to the past can't actually interact with anything."
I don't think this is possible without an artificial construct, and frankly, I doubt if the scientists to discover and first experiment would go to such extreme lengths as developing a method whereby they can be present in a space without affecting any matter or energy around them and also be completely invisible.

I'd guess the only way to achieve that would be to bend space-time around them, but then again, if they did that, it wouldn't even be possible for them to observe anything anyway (light would bend like-wise around them as well).

As I said more than once, the individual reasons why time travel in each instance of time travel hasn't led to a paradox don't especially matter, but I don't even mean they don't MATTER, so much as the fact that they are currently UNKNOWABLE so Agnostics ahoy, trying to imagine now whether it's time police, or failed attempts, or whatever doesn't actually DO anything. The lack of paradoxes shows that there is a lack of paradoxes.
Right, but the lack of paradoxes does not indicate a lack OR presence of future travel to the past. Your argument does not imply your conclusion. Lack of paradoxes does truly indicate a lack of paradoxes, but it doesn't mean that all future time travel to our past is already present in our "stone" past.

Basically you're saying something like "You say that nobody has successfully carried out a paradoxical action while time travelling, but since -I- think that paradoxical actions are inevitable, the only way I can possibly accept your premise is if I assume that your conclusion is 'time travel is impossible'"
Yes. Any travel back in time is likely to cause a paradox, not necessarily by direct action (such as killing your past self), but by the butterfly effect.

But since my conclusion is not "Time travel is impossible" but instead "Whether time travel is possible or not, nobody who has travelled to a time before right now has ever done anything paradoxical FOR WHATEVER REASON" So again, second thoughts, failed attempts, time police, time travel putting you out of phase, whatever the individual reasons happen to be, the evidence seems clear to me (Namely, that the universe hasn't exploded in a puff of logic) that whether you CAN create a paradox or not, no paradox has taken place before january 19th 2009 at whatever time you happen to see this.
I agree that the Universe can't "explode in a puff of logic", but I agree with this because I believe the Universe would just derail onto a new track in the 5th dimension.

Quick question, dev. Assuming time travel is possible, do you think it could ever be possible to travel DIRECTLY to alternate time lines? For example, you don't think we can go back in time and change the past from what we know to be the past, but could we hop from this point in time in the 5th dimension to the same point in time at another point in the 5th dimension? For example, say I had a near death experience, but barely survived. Do you believe there could be another iteration of reality that physically viable in another form where I did die? If not, why not?

ps zhul4nder, right, but what about shorter trips? If I go back in time one hour (and don't do anything which would directly stop myself from making the same trip in an hour), do you really think the butterfly effect would cause such drastic effects? Yes, it would be a different "present" I'd be "returning" to, but it would be fundamentally the same and the changes could quite possibly be entirely unnoticeable.

edit: Wiki's no more legitimate a source than anything else we're referencing or drawing from.
lolz

I'm drawing from scifi movies and TV shows 8)

devonin

01-19-2009, 08:49 PM

Okay, if I assume that your constant insistance on the complete and utter inevitability of any and all use of time travel by anybody for any purpose resulting in paradox, then my only reasonable conclusion given the current existance of the universe, is to conclude that time travel is either impossible, or is never developed by us.

I don't agree with your claims with regards to paradox, but since I'm clearly getting nowhere at all trying to explain myself because you won't back down from your presuppositions about time travel, if I grant you correctness for the sake of argument, the argument stops because my claims run contrary to your basic premises.

Afrobean

01-19-2009, 08:53 PM

devonin

01-19-2009, 08:56 PM

While I'm perfectly willing to -also- entertain the thought and have a discussion about the possibility of alternate parallel universes as a possible consequence of quantum theory (In fact, one of my favourite lines of argument to run past people is that the many-worlds theory of quantum mechanics destroys free will, but that's another thread entirely) and am perfectly willing to accept the possibility that alternate universes are the means by which time travel avoids paradox, I still feel that the theory I put forward in this thread passes the test of Occam better than additional worlds being created.

Afrobean

01-19-2009, 09:31 PM

I still feel that the theory I put forward in this thread passes the test of Occam better than additional worlds being created.
I guess the reason I disagree is just because time travel aside, I'd still be down with the concept of higher dimensions. For me, it's not a matter of "oh time travel creates alternate time lines", it's that these alternate time lines already exist independently of the path time takes for us.

footbull3196

01-19-2009, 10:06 PM

I think that it is impossible to time travel to a point in time where you existed because that would create the paradox where you are in two places at once.

To avoid that, I think that while time traveling, you would have to "jump" a time period, probably before you were born, in order to avoid creating a paradox.

I still don't understand what would happen if, let's say, you travelled to a period in time 2 minutes before you were born. Would you disappear as soon as you were born, or would the person being born disappear?

Afrobean

01-19-2009, 10:21 PM

I think that it is impossible to time travel to a point in time where you existed because that would create the paradox where you are in two places at once.
That's not what a paradox is, however, I will admit that your past self seeing you could be grounds for a paradox. They touch on this in Back to the Future when Doc fears that Jennifer's interaction in the future could cause a time paradox because her future self wouldn't have remembered making the trip in the past.

Incidentally, that whole part of Back to the Future Part II is impossible, because if they jumped from 1985 to 2015, then Marty and Jennifer both disappeared in 1985 and were never seen again (because their return trip hadn't yet "happened").

To avoid that, I think that while time traveling, you would have to "jump" a time period, probably before you were born, in order to avoid creating a paradox.
But even if you hadn't yet been born, the atoms and molecules that make up what you are now would still be present in the past in one form.

I still don't understand what would happen if, let's say, you travelled to a period in time 2 minutes before you were born. Would you disappear as soon as you were born, or would the person being born disappear?
Neither, because that's not what a paradox is. A paradox would be if you go back in time and kill your past self. If your self died in the past, then you could have never lived long enough into the future to make the trip to the past where you killed yourself.

A paradox is something that contradicts itself.

Read this: http://en.wikipedia.org/wiki/Paradox

Then read this, because it actually relates to the idea of time paradoxes: http://en.wikipedia.org/wiki/Grandfather_paradox

edit: found another article more directly relating to the discussion of time paradoxes in general: http://en.wikipedia.org/wiki/Temporal_paradox

slipstrike0159

01-20-2009, 01:09 AM

Listen Afrobean and Devonin, you are both misunderstanding each other because you are comparing two different theories.

Devonin is suggesting that NO MATTER HOW what has been done in the past our present represents what DID happen. Its entertaining the thought that either A: Someone DID go in the past to do something, the results of which being what IS currently or B: It didnt happen, or else it failed, the results of which being what IS currently. The results are the same. *As a side note, this would draw parallel to afrobean's theory of the scientists doing experiments such as pushing back our technological progression to an earlier date. How would you know that future scientists havent already pushed back the technological progression date?
Afrobean is suggesting that the intervention of our past would represent a change from our current dimension string of events to another dimension string of events. So in essence the "Change" would change from track A to track B in such a situation where both track A and track B exist in regards to multiple universes of course.

Everything aside, i believe that whether or not we shift our dimension OR whether or not the results of a travel produce this present, our perception would not be altered (or rather we would not witness our perception being altered.) To explain, if an event was changed where a different string of events are set into play, MY CURRENT PERCEPTION is how i think in regards to my past. If, in essence, 5 minutes ago i was thinking "wow, my best friend matt is pretty cool" and in those 5 minutes (in my time) someone went back to stop his birth and succeded, now my perception would lead to me thinking right now "i dont know anyone named matt". Me 5 minutes ago and me right now now would not see a change because for all intents and purposes, my perception would be BASED off of how things are CURRENTLY. Thus, to think about the meddlings in the past would be irrelevant because whether they happened or not, whether our universe was derailed in a paradox or not, my perception of things is what it is in regards to the current situation of myself and others (aka the present). "I am here now and i am thinking what i am thinking. Regardless of what my past is, this is my present"

That being said, i would return to my idea about a man FAR in the future (relating to our current time) going to a time NEAR in the future (still OUR future but HIS past) because this is a situation in where you can determine "what will happen when we get to that 'near' future point?" NOW you can ask yourself if, first of all, a paradox is capable of happening. Now my belief on the subject of a time paradox is that as long as we progress through -time-, a paradox of any sort would not be a paradox, but rather a problem that exists in a current period of time which would be solved DURING that period having results that produce further progression through time. Thats not necessarily to say that the universe would "work it out" but as soon as we arrive at the problem (paradox) it would be solved in some way shape or form that would produce a result. This result would be our progression from 'our' present and 'our' future. We already know that actions produce results, action reaction. Then the only question worth considering is, could our actions be based on improper ideas about the consequences to the point where someone from the future would have a hindsight thought and say "that was a stupid idea" to the point where they would want to change it? The answer is yes, as is evident in you currently looking back and saying "someone should have done something about hitler earlier than they did". From there we can conclude that we should carefully consider the reaction or "consequences" of our actions such that later a future person would have need to go back. And THAT is the real world application of the time travel theory (among many others of course).

Alternate and multiple universes are a different topic, one that could have correlation but not necessarily causation to the time travel theories.

Now, the time travel theory also produces the inherent question of free will which, in of itself, is yet another topic but also could draw a more objective way of looking at this question. Do we have the free will to do what we want and produce a result based on the free will choice, or was that choice -supposed- to happen in which canceling out the 'free' part of it? As has been said, either we have free will or we have a very vivid illusion of free will. You should then move on to the question of what is your determination as to the idea of "supposed to happen"? Its how we find meaning in things that is the question. Was i "supposed" to meet my friend so he could save my life, did it happen by chance, or do i leave divine intervention and chance out of it only to think of basic "cause and effect" rules? My answer to this is, does it matter? It happened, I met him regardless of HOW or WHY it happened the fact remains that it did. The practical question is 'does -who- (God, chance, free will) i give the credit to affect my later decisions?' If so, then does it affect those decisions in the way you believe you want them affected (free will)? Just remember that there is no reason why free will, divine intervention, and chance cant all play a part in it.